We will investigate the possibility that the perfusion medium bathing a rapidly swelling cornea can act as an extraction medium for stromal components, specifically proteins, glycoproteins and glycosaminoglycans. We will study the swelling behavior and morphology (TEM and SEM) of corneas perfused with a Ca++-free medium compared to corneas perfused with a complete medium and will analyze the perfusate outflow for extracted components. We will also analyze stromal buttons for these same components. In addition, we will specifically examine the organization of the collagen in the posterior lamellae and the response of posterior keratocytes to the expected loss of stromal components.